Methanesulfonyl chloride → tert-Butyl 4-cyano-3,6-dihydropyridine-1(2H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

Methanesulfonyl chloride (0.189 mL, 2.43 mmol) was added to a mixture of tert-butyl 4-cyano-4-hydroxypiperidine-1-carboxylate (500 mg, 2.21 mmol) and N-ethyl-N-isopropylpropan-2-amine (0.579 mL, 3.31 mmol) in chloroform (8.8 mL) at 0° C. The reaction mixture was stirred at 0° C. for 45 minutes, and was then partitioned between dichloromethane and water. The organic layer was dried over anhydrous sodium sulfate, and the dried solution was filtered. The filtrate was concentrated in vacuo, and the residue was dissolved in pyridine (5.5 mL). The reaction mixture was heated to 120° C. for 4 hours, and was then cooled to ambient temperature. The cooled reaction mixture was partitioned between ethyl acetate and water, and the organic layer was washed sequentially with water and saturated aqueous sodium chloride solution. The washed solution was dried over anhydrous sodium sulfate, and the dried solution was filtered. The filtrate was concentrated in vacuo, and the residue was purified by flash-column chromatography (using a gradient elution of 0-100%, ethyl acetate/hexanes) to afford the title compound. 1H NMR (500 MHz, CDCl3): δ 6.55 (br s, 1H), 4.05 (m, 2H), 3.55 (t, J=5.6 Hz, 2H), 2.34 (br s, 2H), 1.46 (s, 9H).

Provenance & Evidence